1. Field of the Invention
The present invention relates generally to fuel cartridges for fuel cells and heaters, and more particularly this invention relates to disposable and refillable fuel cartridges. This invention also relates to fuel cartridges for heaters and direct methanol fuel cells.
2. Description of the Related Art
Fuel cells are devices that directly convert chemical energy of reactants, i.e., fuel and oxidant, into direct current (DC) electricity. For an increasing number of applications, fuel cells are more efficient than conventional power generation, such as combustion of fossil fuel and more efficient than portable power storage, such as lithium-ion batteries.
In general, fuel cell technologies include a variety of different fuel cells, including alkali fuel cells, polymer electrolyte fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, and solid oxide fuel cells. Today's more important fuel cells can be divided into three general categories, namely; fuel cells utilizing compressed hydrogen (H2) as fuel; proton exchange membrane (PEM) fuel cells that use methanol (CH3OH) reformed into hydrogen as fuel′ and PEM fuel cells that use methanol (CH3OH) fuel directly (also known as “direct methanol fuel cells” or DMFC). Compressed hydrogen is generally kept under high pressure, and is therefore difficult to handle. Furthermore, large storage tanks are typically required, and cannot be made sufficiently small for consumer electronic devices. On the other hand, fuel cells using methanol reformats require reformers and other vaporization and auxiliary systems thereby increasing the size and complexity of methanol-reformat based fuel cells. DMFC is the simplest and potentially smallest fuel cell, and holds the most promising power application for consumer electronic devices.
What is desired is a safer and more economical means for storing, transporting, and delivering methanol fuel such that any damage to a device storing, transporting, and delivering methanol that compromises the containment of the methanol is readily recognized.